[LinuxPPS] NTP + PPS falsetick
Marc Leclerc
marc_x at videotron.ca
Wed Jun 16 20:48:27 CEST 2010
Hi,
I made ntp work with the gps or at least communicate but...
so it seem that after a while NTP reject my GPS and PPS input for time
keeping. The only source for time sync is the GPS, I cannot use other
devices and/or remote servers.
I had to add support for my receiver (Trimble Resolution SMT) and
communication wise seems to communicate ok. The pps is also working.
Can anyone make sense of the output from ntpq -p and as cmd from ntpq
and maybe help in understanding whats happening.
I also added some trace from running ntpd from the shell if it may help
if there is any extra info needed please let me know
Thanks
my config is:
driftfile /etc/ntp.drift
server 127.127.29.1 mode 5 iburst prefer
server 127.127.22.0
#I tried with and without delay
#packet delay
#fudge 127.127.29.1 time1 0.020
At start
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 802b yes no none reject clock_alarm 2
2 54001 8011 yes no none reject mobilize 1
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 802b yes no none reject clock_alarm 2
2 54001 8011 yes no none reject mobilize 1
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9654 yes yes none sys.peer reachable 5
2 54001 8011 yes no none reject mobilize 1
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 8 16 377 0.000 -0.538
0.141
PPS(0) .PPS. 0 l - 64 0 0.000
0.000 0.000
>> Note the offset getting larger...
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 1 16 377 0.000 -0.838
0.233
PPS(0) .PPS. 0 l - 64 0 0.000
0.000 0.000
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 15 16 377 0.000 -0.931
0.149
PPS(0) .PPS. 0 l - 64 0 0.000
0.000 0.000
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 1 16 377 0.000 -1.582
0.148
PPS(0) .PPS. 0 l - 64 0 0.000
0.000 0.000
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 5 16 377 0.000 -1.524
0.544
xPPS(0) .PPS. 0 l 37 64 1 0.000 -114.56
0.002
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 14 16 377 0.000 -1.431
0.606
xPPS(0) .PPS. 0 l 62 64 1 0.000 -114.56
0.002
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 7 32 377 0.000 -2.086
0.438
xPPS(0) .PPS. 0 l 7 64 3 0.000 -112.39
2.171
/ # ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 14 32 377 0.000 -2.086
0.438
xPPS(0) .PPS. 0 l 14 64 3 0.000 -112.39
2.171
/ # cat /etc/ntp.drift
2.203
/ # ntpq
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 13 32 377 0.000 -1.679
0.360
xPPS(0) .PPS. 0 l 13 64 17 0.000 -109.26
3.655
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9654 yes yes none sys.peer reachable 5
2 54001 9124 yes yes none falsetick reachable 2
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 8 32 377 0.000 -0.690
0.885
xPPS(0) .PPS. 0 l 40 64 37 0.000 -107.76
4.440
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9654 yes yes none sys.peer reachable 5
2 54001 9124 yes yes none falsetick reachable 2
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9654 yes yes none sys.peer reachable 5
2 54001 9124 yes yes none falsetick reachable 2
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 2 32 377 0.000 -1.317
0.413
xPPS(0) .PPS. 0 l 2 64 77 0.000 -106.28
5.237
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9654 yes yes none sys.peer reachable 5
2 54001 9124 yes yes none falsetick reachable 2
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_PALISADE(1) .GPS. 0 l 5 32 377 0.000 -0.564
0.828
xPPS(0) .PPS. 0 l 37 64 77 0.000 -106.28
5.237
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 54000 9154 yes yes none falsetick reachable 5
2 54001 9124 yes yes none falsetick reachable 2
ntpq> pe
remote refid st t when poll reach delay offset
jitter
==============================================================================
xGPS_PALISADE(1) .GPS. 0 l 8 32 377 0.000 -1.193
0.409
xPPS(0) .PPS. 0 l 8 64 177 0.000 -104.82
6.030
------------ TRACE
......
ML: Primary Timing Packet begin
Timing flag 03
Timing Flags are:
Timing flag value is: 0x3
Getting UTC time
PPS is from UTC
Time is Set
I have UTC info
Time is from GPS
pp->day: 166
TOW: 226149
DAY: 15
TSIP_decode: unit 1: AB #3 14:48:54.000000 06/15/2010 palisade_receive: unit 1: 2010 166 14:48:54.000000
palisade_receive: unit 1: cfc21156.0448d105 Tue, Jun 15 2010 14:48:54.016
refclock_receive: at 898 127.127.29.1
refclock_sample: n 1 offset 0.003264 disp 0.000000 jitter 0.000002
clock_filter: n 8 off 0.003264 del 0.000000 dsp 0.000233 jit 0.000446
select: survivor 127.127.29.1 0.000827
select: combine offset 0.003263909 jitter 0.000446146
poll_update: at 898 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
clock_update: at 898 sample 898 associd 21865
timer: interface update
refclock_transmit: at 914 127.127.29.1
palisade_poll: unit 1: polling event
poll_update: at 914 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
ML: Primary Timing Packet begin
Timing flag 03
Timing Flags are:
Timing flag value is: 0x3
Getting UTC time
PPS is from UTC
Time is Set
I have UTC info
Time is from GPS
pp->day: 166
TOW: 226165
DAY: 15
TSIP_decode: unit 1: AB #3 14:49:10.000000 06/15/2010 palisade_receive: unit 1: 2010 166 14:49:10.000000
palisade_receive: unit 1: cfc21166.043627ac Tue, Jun 15 2010 14:49:10.016
refclock_receive: at 914 127.127.29.1
refclock_sample: n 1 offset 0.003549 disp 0.000000 jitter 0.000002
clock_filter: n 8 off 0.003549 del 0.000000 dsp 0.000233 jit 0.000188
select: survivor 127.127.29.1 0.000827
select: combine offset 0.003548661 jitter 0.000187837
poll_update: at 914 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
clock_update: at 914 sample 914 associd 21865
event at 914 0.0.0.0 c412 02 freq_set ntpd 6.090 PPM
local_clock: mu 913 state 5 poll 4 count 0
event at 914 0.0.0.0 c415 05 clock_sync
local_clock: offset 0.000000000 jit 0.003667564 freq 6.090 stab 0.000 poll 4
refclock_pps: 916 0.303720 0.000000
refclock_pps: 917 0.303703 0.000000
refclock_pps: 918 0.303689 0.000000
refclock_pps: 919 0.303674 0.000000
refclock_pps: 920 0.303659 0.000000
refclock_pps: 921 0.303643 0.000000
refclock_pps: 922 0.303628 0.000000
refclock_pps: 923 0.303614 0.000000
refclock_pps: 924 0.303597 0.000000
refclock_pps: 925 0.303584 0.000000
refclock_pps: 926 0.303569 0.000000
refclock_pps: 927 0.303554 0.000000
refclock_pps: 928 0.303538 0.000000
refclock_pps: 929 0.303522 0.000000
refclock_pps: 930 0.303508 0.000000
refclock_transmit: at 930 127.127.29.1
palisade_poll: unit 1: polling event
poll_update: at 930 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
ML: Primary Timing Packet begin
Timing flag 03
Timing Flags are:
Timing flag value is: 0x3
Getting UTC time
PPS is from UTC
Time is Set
I have UTC info
Time is from GPS
pp->day: 166
TOW: 226181
DAY: 15
TSIP_decode: unit 1: AB #3 14:49:26.000000 06/15/2010 palisade_receive: unit 1: 2010 166 14:49:26.000000
palisade_receive: unit 1: cfc21176.0449412c Tue, Jun 15 2010 14:49:26.016
refclock_receive: at 930 127.127.29.1
refclock_sample: n 1 offset 0.003257 disp 0.000000 jitter 0.000002
clock_filter: n 8 off 0.003257 del 0.000000 dsp 0.000233 jit 0.000361
select: survivor 127.127.29.1 0.000827
select: combine offset 0.003257224 jitter 0.000360524
poll_update: at 930 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
clock_update: at 930 sample 930 associd 21865
local_clock: mu 16 state 5 poll 4 count 4
local_clock: offset 0.003257224 jit 0.003618817 freq 6.140 stab 0.018 poll 4
refclock_pps: 931 0.303495 0.000000
refclock_pps: 932 0.303478 0.000000
refclock_pps: 933 0.303467 0.000000
refclock_pps: 934 0.303469 0.000000
refclock_pps: 935 0.303463 0.000000
refclock_pps: 936 0.303465 0.000000
refclock_pps: 937 0.303460 0.000000
refclock_pps: 938 0.303459 0.000000
refclock_pps: 939 0.303456 0.000000
refclock_pps: 940 0.303452 0.000000
refclock_pps: 941 0.303452 0.000000
refclock_pps: 942 0.303447 0.000000
refclock_pps: 943 0.303448 0.000000
refclock_pps: 944 0.303445 0.000000
refclock_pps: 945 0.303442 0.000000
refclock_pps: 946 0.303439 0.000000
refclock_transmit: at 946 127.127.29.1
palisade_poll: unit 1: polling event
poll_update: at 946 127.127.29.1 poll 4 burst 0 retry 0 head 0 early 2 next 16
....
More information about the LinuxPPS
mailing list